Of Ecosystem Processes Flashcards
7 cards from real Ecology practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Of Ecosystem Processes flashcards as text
What does the 'hydrological cycle' primarily describe?
Answer: Continuous movement and recycling of water on Earth
The hydrological cycle tracks water's movement through evaporation, condensation, precipitation, and runoff across Earth's systems.
Which of the following best explains why biomagnification occurs in food chains?
Answer: Persistent toxins accumulate faster than organisms can excrete them
Biomagnification happens because fat-soluble, persistent pollutants like DDT accumulate in tissues and are not broken down, so concentrations increase at each trophic level.
What is the primary driver of the sulfur cycle's short-term component in terrestrial ecosystems?
Answer: Decomposition of organic sulfur compounds
Microbial decomposition of organic sulfur in dead matter releases sulfur back into the soil and atmosphere on short timescales.
Which concept describes the maximum rate at which an ecosystem can produce organic matter, regardless of resource limitations?
Answer: Potential primary productivity
Potential primary productivity is the theoretical maximum production an ecosystem could achieve under optimal climatic conditions without nutrient or resource limitation.
What is 'litterfall' and why is it important to ecosystem processes?
Answer: Dead plant material deposited on the soil surface, fueling decomposition
Litterfall—shed leaves, twigs, and other plant parts—is the primary input of organic matter to the forest floor and drives nutrient cycling through decomposition.
Which abiotic factor most strongly limits primary productivity in open-ocean ecosystems?
Answer: Nutrient availability (especially nitrogen and iron)
The open ocean is nutrient-poor (oligotrophic), and low concentrations of nitrogen and iron severely limit phytoplankton growth despite adequate light.
What is 'net ecosystem productivity' (NEP)?
Answer: GPP minus all autotrophic and heterotrophic respiration
NEP equals GPP minus total ecosystem respiration (both autotrophic and heterotrophic), representing the net carbon balance of the whole ecosystem.